Thread: Trencher for Oak Wilt Suppression

Thanks for the info. I really hadn't paid much attention in the past, but I do have quite a few customers with good stands of oak. Most of these are on rocky, steep ground. I'll be paying much better attention to the problem in the future. Time to get educated!

There is a stream of revenue dealing with the fallout from oak wilt but I'd rather see it prevented. It's disheartening to see 200 year old trees die in a matter of weeks.

Protecting roots, keeping tree wounds to a minimum, and proper pruning and sealing wounds help to keep the trees healthy but there isn't much you can do once an infection center starts that doesn't involve isolation. Individual treatment of trees with propocazinole may help protect individual trees but it doesn't stop the fungus from spreading to other trees. I've been working with oak wilt for almost 20 years but have never advertised it much because cedar clearing kept me busy and a lot of oak wilt remediation requires hand-cutting and climbers and I can't recycle much of it but we take on some fairly large projects several times a year.

My advice, get educated if you work in central Texas or between TX and Minnesota and understand the life cycle of the fungus, oak tree varieties, and it never hurts to have a knowledgeable arborist on staff or in a close working relationship.

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Update:
First pic: Trenched through nearly solid caliche under a few inches of soil and idea of visibility
Second pic: deeper loam above a layer of clay.
I completed the first leg of the trenching project last week. Unfortunately, I had a lot of problems with the trencher so I didn't get to take many pictures.
So far, I am impressed with the power and speed of the Bobcat 405 trencher. Considering how hard my ground is and it was my first time using a trencher on a skid steer, I think I made good time. I trenched one line a little over 1/4 mile and several tie in trenches between 100 and 150'. I have a secondary trench of about 1/4 mile that I will do in the fall and a few more tie in trenches.

The good:

-Speed at which I can trench to 5' depth and ease of use. I was surprised how easy it was to learn.
-High flow trencher has plenty of power at only 2100 rpm engine speed
-Trenched through solid limestone, hard caliche, and dense, hard-packed clay.
-More of a loader feature but ability to dial in speed to 25% for smooth operation
-Hydraulic side-shift feature
-Dual augers really do move the material away from the hole quickly
-Surprisingly good on fuel even though it is a high flow attachment

The Bad:

-Visibility. Trencher is wide and blocks a lot of my view
-Vibration in loose rock- Felt like I was running an impact hammer until I dialed down engine RPM and let trencher settle in.
-Chain came off three times. Hurt my back getting it back on WITH the help of my excavator and binder straps
-Lost almost all standard bullet teeth. Bobcat sales rep brought me a different style tooth and they seemed to stay in the pockets better
-Cups broke where there was hardfacing. (heat issue?)
-Sheared 4 grade 8 bolts on bullet teeth holders and another bent
-Hydraulic side-shift feature. Have to leave the cab and pull lever on valve block then get back in the cab to side-shift. Seemed to move on its own and that is one possible cause of the chain coming off. Broke two 3500 lb straps trying to keep boom in the middle. Finally just moved it all the way to the right side and left it there but it worked better in the middle.
-Boom length. I wanted 5 foot dig depth but it ends up being about 9' long in total. Makes hauling difficult and I am fairly certain that extra foot is causing extra vibration and play which leads to more machine vibration and may be another factor in losing the chain. Shop may shorten boom to 4'.
-Chain tensioner location. Not thought out well.
-Trench cleaner (fits on top and flips down) got loose immediately so I removed it as well as a guard that a tooth caught and bent.

I had a weld break on the right side auger guard. Thinking the side shifting put too much pressure on it while I was trenching. Though it looks beefy where it attaches to the frame with bolts, I can see where the welds were not adequate between guard mounting plate and guard. This attachment weighs about 2k lbs. Everything needs to be heavy duty and I obviously found the weak points.

Overall, I am impressed with the power. Bobcat is going to help me figure out why the chain kept coming off (tension was fine) and get the kinks worked out of it. My dealer was responsive to my concerns and said they would help me get it right. I was disappointed, though, that one suggestion is to shorten the boom. I am sure I paid more for a longer boom and was hoping that it would work as advertised but the conditions we have here can be fairly extreme for most types of digging. Seems to me that the front roller should have teeth but it's a smooth wheel. With the vibration and a spring inside the boom, it's conceivable that it bounces enough to loosen tension enough to throw chain. I can't describe how much it sucked to put that back on in the woods. Maybe shortening will work and I have the excavator to dig deeper if necessary.
Thoughts from those who have used a skid steer or ditch witch style chain trencher?

For those that are curious, I will update more when I get it back and have a chance to use it.

Attached Images

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Why do you have to trench through the rock, do the tree roots make it down there? Or are you installing a plastic barrier like for bambooPosted via Mobile Device

The soil horizons in the hill country of texas can vary. Sometimes you will have rock down to 2 ft then clay or caliche. Roots don't like caliche but they can go through that horizon on their way to someplace else. there generally are not roots in solid rock BUT it's tough to know how deep the rock (or shallow) it is and if it's just a flat table like piece of limestone, there could be roots before or after it. Best to do a continuous trench and check for roots at your deepest points. It's a PITA but I had to try.

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"Life is tough, but it's tougher if you're stupid."

Interesting observations on the trencher. It sounds like you're finding out flaws that your rep needs to know about. Maybe you're the guinea pig for the 5'?

I've been the guinea pig for too many things! I buy and sell a lot of attachments that I use on the ranch or at work. What doesn't work for me I sell. I hold onto the things that do work. Sometimes, it takes awhile to get proficient with something new. There are always flaws in these things and I've seen attachments that just weren't worth a dime and some that took awhile to get the bugs out of. I think this attachment will do a good job and be reliable once i figure out what isn't set up right. I don't remember Bobcat redesigning the complete unit and I don't remember a 5' option until recently. Maybe it's an after thought and just a tad too long to hold up. We shall see.

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"Life is tough, but it's tougher if you're stupid."

Cool project hopefully it works out for you. You are right there is nothing worse then seeing 200 year old oak trees dead. We have the same problem here in San Diego but our oak trees get the gold spotted oak borer. They have killed hundreds of acres of oak trees. There is not cure or end in sight for us. They cannont figure out how to get rid of this thing. They suspect it came in on firewood from arizona.

Cool project hopefully it works out for you. You are right there is nothing worse then seeing 200 year old oak trees dead. We have the same problem here in San Diego but our oak trees get the gold spotted oak borer. They have killed hundreds of acres of oak trees. There is not cure or end in sight for us. They cannont figure out how to get rid of this thing. They suspect it came in on firewood from arizona.

That's generally how things get out of whack. An invasive species or pathogen blows in, is carried in via firewood, pallets, or lumber, and there is no natural resistance. Imagine how lucrative a cure for your problem would be if you got in on the ground floor of a treatment even if it's not 100%? I imagine even a broke state like CA would find the money to subsidize landowners who are trying to save their trees. Texas has or did have some grant monies for some oak wilt treatments like trenching. I'd personally rather see my tax dollars go towards preserving old trees than go to putting people in free housing or a lifetime of food stamps.

I know that along the PCH there have been a lot of sudden oak deaths. Different pathogen than oak wilt but similar results.

For bugs, there will probably be some type of other bug used to control them until that predator bug gets out of balance and affects something else.
Where I live there are plenty of warnings and information available for contractors to learn about oak wilt. I've talked to tree companies that have NO knowledge whatsoever. To me, that is inexcusable ignorance but as you know there are too many fly-by-night contractors that muddy the water for the rest of us and do anything for a buck even if there are quarantines zones for moving infected wood.

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"Life is tough, but it's tougher if you're stupid."

Yellowdog, I wish you the best of luck in saving the trees on your ranch. I also wanted to thank you for the info you posted about Oak Wilt. I've been doing so searching seems like there have been cases reported in southern Louisiana.Posted via Mobile Device